The present applicant has invented previous blast aerators, also referred to as quick-release aerators, as disclosed in the applicant's U.S. Pat. Nos. 3,788,527, issued Jan. 29, 1974, and 3,915,339, issued Oct. 23, 1975. In the aerators of such patents, a considerable volume of compressed air is stored in a tank and is quickly released by the opening of a piston valve, to produce an air blast. The piston valve is movable in a cylinder and is initially closed by air pressure in the cylinder, but is quickly popped open when the air pressure is exhausted from the cylinder by the reversal of a three-way control valve.